Complex left appendage morphology is associated with Embolic Stroke of Undetermined Source

Introduction: Variations in the left atrial appendage (LAA) morphology are associated with different embolic risk in patients with atrial fibrillation (AF). Data are scarce regarding the association between LAA morphology and Embolic stroke of undetermined source (ESUS).Patients and methods: Using cardiac computed tomography (CCT) scans, LAA morphology was categorized as either chicken wing (CW), cactus, windsock, or cauliflower. Furthermore, we examined the presence of large secondary lobes arising from the main lobe, considering their existence as indicative of a complex LAA morphology. LAA morphologies were compared between ESUS (n= 134) and AF patients (n= 120); and between ESUS patients with (n= 24) and without (n= 110) subsequent AF diagnosis during long-term follow-up.Results: ESUS patients had a significantly higher prevalence of cauliflower morphology compared to AF group (52% vs 34%, respectively, p= 0.01); however, no significant difference was found between the groups when categorizing LAA morphology to either CW or non-CW. ESUS patients had significantly higher prevalence of large secondary lobes compared with AF patients (50% vs 29%, respectively, p= 0.001). When comparing ESUS patients with and without AF diagnosis during follow-up (20–48 months of follow-up, median 31 months), there were no significant differences in the prevalence of the “classical” morphologies, but large secondary lobes were significantly more prevalent among those withoutsubsequent AF diagnosis.Conclusion: ESUS patients have a high prevalence of complex LAA morphology, which might be associated with an increased risk for thrombus formation even in the absence of AF.